because they know nothing at all!! of coarse
Native American pre-Columbian oral literature (Native Americans, influenced by Benjamin Franklin)
A sonogram is 100% accurate, insomuch as it's basically a picture. Interpretations of that picture may vary, and may or may not be accurate, but the sonogram itself is a sounding of whatever is being...
99% effective.
many people say that it is, yet, it has been proven inaccurate on many occasions.